1. Field of the Invention
The present invention relates to a hydraulic motion transducer, and more particularly to tactile and movement sensation generators, as used in motion simulators, for example a home theater simulator.
2. Description of the Prior Art
A traditional movie involves the use of two viewer senses: the sight and the sound. For more than fifty years this was the way of transmitting sensations to viewers. However, recently, new movie technologies have allowed the use of other senses in order to provide an even more realistic experience for the viewers. The tactile and equilibrium senses were added to sight and hearing in order to allow viewers to even xe2x80x9cfeelxe2x80x9d action during a movie.
In many places where the affluence of clients permits, expensive technologies have been implemented, especially in amusements parks. For example, U.S. Pat. No. 5,678,889 to Purcell discloses a modular assembly of theater seats moved by a hydraulic cylinder while U.S. Pat. No. 3,865,430 to Tanus presents a theater chair movable by remote control. However, the hydraulic motors used for moving these chairs in amusement parks have a built-in moving system and are consequently large and expensive. They may only be employed in a large scale application, such as in public theaters. These technologies may not be employed for the large majority of movie screens, which are the home theaters.
Nevertheless, in recent years, new devices for providing tactile sensations to movie viewers emerged in the field of home use. The U.S. Pat. No. 4,750,208 to Yamada et al. disclosed an audio-band electromechanical vibration converter that provides small amplitude vibrations according to a soundtrack. Like this patent, most devices in the field usually comprise a magnetic vibration generator that reproduces the low frequency vibrations of movie soundtrack on contact with the viewers skin. Other devices transmit vibrations to the body of the viewer""s chair. However, only very small amplitude vibrations may thus be transmitted to the viewers using those devices and this kind of vibrations do not always reflects the action occurring in the movie. Moreover, such small amplitude vibrations are attenuated by the chair cushion in the case of devices that transmit vibrations to the viewer through the chair, so the viewer may barely feel those tactile sensations. Current devices do not provide enough amplitude of the movements for creating real movement sensations for movie viewers. Since they only perform very simple signal processing such as filtering, they do not provide controlled movements.
It is therefore an object of the present invention to provide a multi-sense theater chair transducer system for use with a chair or a sofa, that provides both tactile and movement sensations to a home movie viewer by transmitting these sensations to the viewer via the chair or the sofa.
It is another object of the present invention to provide a multi-sense chair transducer system that receives the sound output from a sound system having a plurality of outputs (currently available sound outputs for most sound formats are front, back, left, right, center and subwoofer sound outputs) and computes these sound signals in order to provide directional tactile and movement sensations to the viewer according to the sound signals. In this manner, the movie viewer will feel sensations which are synchronized with the current action from the movie being played.
The present invention comprises three main modules: the first one is the main encoder module which receives the sound signals from a video system such as a digital video disk (DVD or LD), a VCR system, a computer or a simple TV set and performs a digital sound signal analysis in order to output movement codes. Any source of video signal that also comprises a form of sound signals, such as analog or digital encoded sound signal may be employed as well, such as a satellite decoder (SAT) or a PC running a video game. The second module is the motors controller which receives the movement codes from the main encoder module and outputs a power drive signal for the motors in such a way that the motors may run in correlation with the initial sound signals and provide the tactile and movement sensations to the viewer. The mechanical movement module is the last module and it comprises the electrical motors as well as a shaft encoder and a protection circuit for the motors. The present application will only cover the second and the third module of the present system, i.e. the motors controller module and the mechanical movement module.
The movement generator module preferably comprises four devices, each intended to be placed under a corner of a platform, or a leg of a chair or of a sofa in order to transmit the tactile and movement sensations to the viewer. Each device comprises an electrical motor working in association with a cam system or a hydraulic system in order to generate reciprocate movements. The term movement will be used throughout the present text for covering the range of movements starting with vibrations having very small amplitudes and ending with movements having higher amplitudes of the range of one inch. Thus, in the present text, the term movement sensations will cover both sensations involving the tactile sense (created by small amplitude vibrations) and the sense of equilibrium (sensations created by higher amplitude movements) of a movie viewer.
According to the present invention, when a signal is processed by the main encoder module, the movement codes are sent to the motors controller which then activates the motors as commanded by the main encoder, in accordance with the sound signals processed. For example, in a movie having a plurality of output sound signals such as Dolby Surround (TM) or Dolby Digital (TM), one to six different sound signals may currently be available. These signals are processed in real-time by the main encoder which outputs movement action codes for the motor controller and this last one drives the motors for providing directional movement sensations to the movie viewer. For example, with such technology, if a helicopter passes from the left to the right of the screen, the sound will first be output by the left speaker and then gradually pass to the right speaker, so the viewer hears the real passage of the helicopter. The corresponding movement sensations will be at first movements of the device(s) placed under the left leg(s) of the viewer""s chair and this movements will gradually pass to the right leg(s) of the chair for providing the same sensation of movement as the sound does.
By using the tactile and equilibrium senses in combination with the sight and the hearing of the movie viewer, the present invention provides tremendous sensation of realism that has never been reached before in a home theater.
According to a preferred embodiment of the invention, there is provided a home entertainment transducer system for generating movement in a chair having at least three legs is provided, the system comprising:
chair leg movement generator means for generating reciprocate movements at each one of said leg of a chair; and
motor controlling means for processing a series of movement input codes and generate in response to each input code a sequence of power drive signals for powering said movement generator means to produce small amplitude reciprocate movements in said chair according to said movement codes.
According to another preferred embodiment of the invention, there is provided a movement generator for producing mechanical movements in a chair having at least three legs, the movement generator comprising:
a chair leg receiving surface for supporting a leg of said chair and for transmitting said mechanical movements to said chair;
rotative means for lifting and lowering at small amplitude and low frequency said chair leg receiving surface; and
an electric motor coupled to said rotative means.
According to the invention, there is also provided a movement generator for producing small amplitude movements, comprising a supporting surface, a first piston slidable within a chamber for lifting and lowering at small amplitude the supporting surface, a second piston slidable within the chamber for driving up and down the first piston under hydraulic fluid pressure, the first and second piston providing a piston and cylinder arrangement, and an electric motor for linearly reciprocating the second piston in accordance with power drive signals communicated to the electric motor.
Preferably, the movement generator includes a ball screw connected to the electric motor and the second piston, the second piston carrying out axial movement in response to a torque transmitted by the motor to the ball screw.